In one embodiment of the present invention, an apparatus for injecting liquid fertilizer into a water flow line in a sprinkler system, includes an injector mechanism body having a water inlet and a water outlet adapted to be connected in the water flow line of the sprinkler system so that water flows through at least a portion of the injector mechanism body, a plunger chamber, a plunger movably positioned in the plunger chamber, a paddle wheel positioned to be rotated by water flowing through the injector mechanism body, a plunger gear coupled to the paddle wheel and the plunger so as to rotate when the paddle wheel rotates so as to move the plunger back and forth within the plunger chamber and a valve assembly secured at a fixed location in the plunger chamber.
In one embodiment of the present invention, the valve assembly includes a first retaining member, a second retaining member and a valve member positioned in a space between the first and second retaining members. In one embodiment, the valve member is moveable in the space between the first retaining member and the second retaining member.
In another embodiment of the present invention, the valve member and the first retaining member each include a conical surface and the conical surface of the valve member seals against the conical surface of the first retaining member so as to prevent fluid flow through the valve assembly in at least one direction.
In yet another embodiment of the present invention, the valve member includes a flange, the second retaining member includes a projection and the flange of the valve member is supported on the projection so as to provide a fluid flow path around the flange. In one embodiment, the valve member includes two flanges separated by two notches, the second retaining member includes four projections and two of the projections engage the notches of the valve member and the remaining two projections support the flanges of the valve member so as to form fluid flow paths around the flanges.
In another embodiment, the valve assembly permits fluid flow in only one direction.
Additional features will become apparent to those skilled in the art upon consideration of the following detailed description of embodiments of the invention and accompanying drawings.